Drifting-valve for locomotives.



J. W. BUCKLAND & R. McVlCAR.

DRIFTING VALVE FOR LOCOMOTIVES.

APPLICATION FILED JUNE 14, SH.

Patented Nov. 12, 1916.

Joseph W. Buckland.

Witnesses:

lnvenlbrs Per HHDrne OSEZPH W. ZBUGXLAND All?!) EQBERT MQVICAR, OI?MONTREAL, QUEBEC, CANADA.

DRXETIEQfi-VALVE FOR LGQOMQTIVES.

earner.

Application filed June 14, 1917.

To all whom 2'25 may concern:

Be it known that we, .lossrn WELLINGTON BUCKLAND and ROBERT lilo-Violin,both of the city of Montreal, Province of Quebec, li o-- minion ofCanada, have invented certain new and useful Improvements inDrifting-Valves for Locomotives; and we do hereby declare that thefollowing is a full, clear, and exact description thereof.

This invention relates to the class of drifting valves which supply livesteam to the locomotive valve chambers and cylinders when the throttleis closed and the engine is in motion.

Our invention has for its object to solve this problem by asubstantially direct steam connection from the boiler to the main valvechamber, and to adapt an automatic mechanism to minimize the shocks dueto its operation.

The invention may be said broadly to consist of a unitary differentialvalve constructed and arranged to have constantly imparted thereto atendency to remain closed, and, under abnormal conditions, when thelocomotive is drifting for instance, to be sensitive to the atmosphericpressure which opens it and in which the atmospheric pressure isaugmented by the auxiliary steam in sustaining it in open position. Theuuxiliary steam tends to minimize the shock at both ends of travel. Thisphenomenon is due to the fact that the relief steam at the instant itenters the valve casing deflected upwardly into the annular cavity inthe underside of the valve, the effect being that there a tendency tokeep the valve up, and conseiguently open. The diiierential valve andthe casing are specially constructed to eii'ect communication betweenthe steam duct leading to the main valve chamber and the upper side ofthe diller entiul valve thus maintaining a uniformity of pressure on theupper side and a small area of the underside oi the difierentiul valvewith the eli'ect that a drop in pressure in the cylinder and main valvechamber is inshuihmeously felt on the upper side of the vulvc.

More specifically stated the invention conof a diiicrentiul valve andvalve casing, of substantially inverted conical axial section andprovided with an annular valvular extension near apex, the inverted basebeing in sliding engagement with, the interior of a cylindrical portionof the casing, While the Specification of Letters latent.

Serial No. 17%,81G.

portion of the latter surrounding the annular valvular face contains theauxiliary steam port to which the supply pipe from the boiler 18connected. This lower end of the casing terminates in a steam passageadapted to be connected directly to the main valve chamber, and havingan upstanding vane within which the apex of the differential valveprojects. In the preferred embodiment of our invention uniformity ofpressure is obtained on the upper side of the differentiel valve and theportion of the lower side within the annular valvular face by an axialduct through said differential valve which has a ehmnhered interior.

For full comprehension, however, of our invention, reference must he hadto the accompanying drawings in which similar refcrence charactersindicate the sameparts and wherein:

Figure 1 illustrates,partly in elevation and partly in sectional view, aportion of a locomotive with our invention applied thereto;

Fig. 2 is a sectional view of our improved drifting valve takendiametrically through the same in the plane of the auxiliary steam pipe;and

Figs. 3 and 4 are horizontal sectional views taken on lines 3-3 and l-lrespectively, Fig. 2.

A portion of the boiler barrel is indicated at l), the main valvechamber at (Z and the engine frame at 6.

Our drifting valve may be connected to the main valve chamber at anyconvenient point on the steam admission side of the valve, the chamberbeing bored and tapered to have the shank 2 of the casing of our valvescrewed therein.

Our differential valve consists of a substuntielly inverted colloidalmember 3 chambered as at 4 and preferably having an opening 5 axiallytnz'o h its apex which is truncated and or nozzle. form. Near the apexan annular or cylindrical valvular extension 6 is provided and theinverted base is extended in a short cylindrical part 7; thiscylindrical port"? and the valvular extension 3 being; provided withcircumferential grooves for packing rings 8. The annular extension 6 isconnectecl to the nozzle by n web which constitutes with the nozzle andextension the minor face of the differential valve proper.

The casing of our velve is also of inverted fifi li fted thus uncoveringthe port 31, 3'2 and 3:.

conoiclal form terminating at its apex in a tubular part constitutingthe shank 2 before mentioned, while its base 10 is of cylindrical formand of sutliciently greater depth than the cylindrical part 7 of thevalve to permit axial movement of the latter. Between the shank 2 andthe cylindrical portion 10 the casing is of increased thickness in aplane transversely to the annular 'alvular extension of the valve andsubstantially midway of its depth in its normal or lowermost position,an annular steam port 12 being formed in this-part of the casing, and apipe coupling boss is beinc cast in the casing in cone munication withthe port 12. The coupling has the steam pipe 16 leading from the boiler,connected thereto. In order to obtain a comparatively even distributionof the auxiliary steam to all portions of the. port 12, a bushing 30 islocated within the portion of the casing! containing the port.- and ithas 3 openings 31, 32 and 33 while the port of the casing is eccentricto the bushing 30 thereby imparting to the part 12 a greater capacity atits intake end and diminishing to the second and third ports 32 "thepressure 37 through the steam of our valve, drops t pressure less thanatmospheric the atmospheric pressure will lift the "ifi'erential valveand admit steam from the steam pipe lddirect to-passage 17 and the mainvalve chamber.

A cap 18 closes the top of the casing. The upper end of the tubularshank 2 is projected in the form of a vane .25 and the undcrsidi ot' thevalvular extension 3 is recessed to form a chamber 50 which receivesthis vanc with sutlicient clearance to have the entire uiulcr-sm'faceot' the differential valve within the diameter of the valvularcxtcnsioncxposcd to the pressure oi the auxiliary steam when our valve is raised.

In the operation of our invention. the en- 'gine being in motion, whenthe throttle is closed and the steam pressure. in the main valve chamberand cylinder drops below at mosph'erie pressure, the ditl'crcutial valveis passage 17. 1

and admitting auxiliary steam direct to the main engine valve chamberthrough steam This flow of the steam first exerts a effect on the valvebeing deflected 11 by the vane 25 into contact with t .e 1 face of thevalve proper. The steam i: deflected downwardly and followir surface ofthe nozzle is concentrated in a solid jet at :1 point immediatelybeneath and in close proximity to the truncated apex sure actingdirectly in the lower side of the lifted valve and the suction abovementioned,

on the upper side thereoty all maintain the valve in its lifted and openposition until the engine comes to a stop or pressure builds up in thecylinder and main valve chamber. The effect is that the high pressureexerted through the opening: in the valve on the upper side. lowers itand closes the ports 31 32 and 33 which cuts otl the steam. This is thenormal position of our valve while the enpine is running under steam andit remains in this position until there is another drop in pressure inthe cylinder, as above described.

lVhen the throttle is opened and the (litterential alvc is in its upwardposition the sudden rise in pressure on the large diameter of the latterwould have a tendency to drive it to its lowermost positionwvithconsiderable shock. The combined action of the chamber no and pocket 26minimizes this shock in the followin manner. The. annular pocket :26surrounding the vanc and iucloscd by the. outer wall of om t-usingserves to contain some of the high pressure steam from the relict' pipcll' which cushions the fall of our valve and absorbs the shock owin tothe fact of the relatively sni'allz area oi thc an nular passagebetwecnthc-top of the vane and the contlgaous portion of the recessedIllidcrsidc ot' the valve wnich creates suflicicnt. friction to retardthe tinal downward.

movement of the valve. The steam containcd in the chamber 4 of. ourvalve and,

which can escape only by the restricted opening when this valve islifted hv a dropin pressure in the cylinder, in a similar mannercushions the blow on the cap and absorbs the shock.

What we claim is as follows:

1. A valve of the type described comprising a dificrential valvewithtruncated apex of nozzle form and an annular valvular extension nearits apex and ofless diameter than the base of the i-'alve. tlie,n1inorface of the said differential valve'having an annular concavityconcentric to and between the said apex and annular valvular extension:a valve lilo casing containing the said differential valve and havin asteam supply port controlled by the saif annular extension, a steamoutlet passage in close proximity to the port and inclosing the apex ofthe differential valve,

and an annular bafller-vane forming the intake end of the outletpassage, the said vane registering with the said annular cavity, and

the interior of the opposite end of the casing lei/being of cylindricalform and of sufficient dept to accommodate the differential valve in itsoperation of opening and closing the steam port, the casing having anopening to the atmosphere at a point at which atmospheric pressure willbe exerted upon the exterior of the differential valve for the purposeof actuating the latter when pressure within the same becomes less thanatmos pheric, and means whereby permanentiy open communication iseffected between the cylindrical portion of the casing and the steamoutlet passage.

2. A valve of the type described comprising a differential valve with anannular valvular extension near one end and of less diameter' than theopposite end of the valve and and having a nozzle in its axial line anda surrounding annular, concavitypa valve casing containing thedifferential valve and aohaving a steam supply port controlled by saidvalvular member, a steam outlet passage in close proximity to the portand the said interior of the casing having an integral annularhafller-vane forming the inner end of the said steam outlet passage andregistering with the said annular concavity, and the interior of theopposite end of the casing being of cylindrical form and of sufficientdepth to accommo- 40 date the differential valve in its operations ofopening and closing the steam port, the

casing having an opening. to the atmosphere at a point at whichatmospheric pressure will be exerted upon the exterior of thedifferential valve for the purpose of actuating the latter when pressurewithin the same becomes less than atmospheric, and means wherebypermanently open communication is effected between the cylindricalportion of v the casing and the steam outlet passage.

3. A valve of the type described compris- .-in a differential valve withan annular va vular extension near the minor end of the valve and havinga nozzle projecting from its minor side in its axial line; a valvecasing containing the differential valve and having a steam supply portcontrolledfby said valvular member. a steam outlet passage in closeproximity to the port and in.

' the axial line of the differential valve, an

annular bafi'ier-vane formed-integrally with the casing and forming anextension of the passage toward the valve, and the interior of theopposite end of the casingbeing of cylindrical form and of sufficientdepth to the differential valve for the purpose of actuating the latterwhen pressure within the same becomes less than atmospheric, and anaxial opening through the valve whereby permanently open communicationis "effected between the cylindrical portion of the casing and the steamsupply passage.

4. A valve of the type described comprising a differential valve with anannular valvular extension near one end and of less diameter than thebase of the valve and having a nozzle projecting from its minor side inits axial line, the external surface of the valve between the annularvalvular member and the base presentinga circumferential concavity; avalve casing containing the differential valve and having a steam supplyport controlled by said annular valvular extension, a steam outletpassage in close proximity to'the port and'in the axial line ofthedifferential valve, 'an annular bafller vane formed integrally withthe casing and forming an extension of the passage toward the valve, andthe interior of the opposite end of the casing being of cylindrical formand of sufficient depth to accommodate the differential valve in itsoperations of opening and closing the steam port, the casing having anopening to the atmosphere coinciding-with the concave portion of thevalve, and the differential valve having an axial opening therethroughwhereby permanently open communication .is effected between thecylindrical portion of the casing and the steam outlet passage at apoint contiguous to the nozzle.

5. A valve of the type described comprising a differential valve with avalvular member near the end and of minor diameter and having a nozzleprojecting from its minor side in its axial line; a valve casingvcontaining the differential valve and having an eccentric steam su plyport controlled by said valvular mem )er, and a bushing with a pluralityof orts therein commu nicafing with the suppy port a steam outletpassage in close proximity to and in direct communication with thesupply ort, and the interior of the opposite end 0 the casing being ofcylindrical form and of SllfllClGXll', depth to accommodate the differential valve in its operation opening and closing the steam port, thecasing having an opening to the atmosphere at a point vat whichatmospheric pressure will be exerted upon the exterior of thedifferential valve for the purpose of actuating the latter when pressurewithin the same becomes less than atmospheric, and means whereby apermanently open communication is effected 4 rangement, an annular vaneforming an in between the cylindrical portion of the cas Ward extensionof the outlet port and inter ing and the steam outlet'passage. I

6; In a drifting valve the combination differential 'valve adapted tocontrol the with a valve casing having steam intake and steam inletport,the minor pressure 'face of the diflerential valve having an axiallydisoutlet ports inielative rightangular arrangement, an annular vaneforming an inward extension of the outlet portend intersecting thesteam'inletport, of an automatic differential valve-adapted to controlthe steaminlet port, the minor pressure face of posed' nozzle and asurrounding annular chamber in registering. relation with the vane, andan axial port through the said .difi'ere'ntial valve and nozzle wherebyan open communication is effected between the the differential valvehaving anaxially disoutlet port'inth vicinityoi the nozzle and posednozzle and a surroundingaannulaf the major pressure face to? thedifierential chamber in registering relation with the valve. c vane, andmeans whereby an open communicationis effected between the-outlet port 1names to this specification in the presence inthe vicinity of the nozzleand the major of two witnesses pressure face of the differential valvel;l JOSEPH W. BUCKLAND. 7. In 'a drifting valve-thefcombination ROBERTMCVICAR. with-a valve casing having steam intake and p i itnesses:outlet ports in relative right-angular ar- GORDON G. (20010:,

WILLIAM J. G. Hnwnrsonh seating the steam inlet port, of an automatic Intestimony whereof"We-nave signed our

